Hair straightener



FIG. 1 is the perspective view of a hair straightener, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top elevational view thereof;

FIG. 7 is a bottom elevational view thereof; and,

FIG. 8 is a perspective view thereof, shown in a position of use.

The broken lines of the drawings depict portions of the hair straightener that forms no part of the claimed design. 

CLAIM The ornamental design for a hair straightener, as shown and described. 